I cared about animals yet experimented on them.

During my PhD in neuroscience, I worked with mice. I injected viruses into their brains to trace neural circuits, and then killed them so we could visualize the tissue under a microscope. Over time, this work slowly tore me apart, as I cared about animals yet was the one inflicting harm. 

I want to share my experience because I know it is not unique. Many researchers carry this kind of distress in silence, and I carried it for years before I understood what it was. 

My fascination with the brain started early. In high school, I competed in the 'Neuroscience Olympiads' and fell in love with the subject. When I entered my PhD program, I wanted to become a neuroscientist, the first in my family to reach that level, someone who might one day contribute to understanding brain diseases. These were honest aspirations, and they made it feel natural to go along with what I was told about the work ahead. 

In academia, animal research is presented as an unquestioned necessity. We are constantly reminded that fundamental neuroscience is crucial to understanding disease and that animal models are how we make progress, but that we shouldn't worry because suffering is minimized through strict ethical protocols.

These narratives are the product of a cultural belief system so deeply embedded in our society that the exploitation of animals for human benefit has come to seem normal and inevitable. So normal, in fact, that rational and compassionate people can participate in harmful practices without ever stopping to question them. 

Within this framework, I built my own set of justifications. I told myself that the government funds this research regardless of whether I participate so it will happen with or without me. When doubt crept in, I reassured myself that at least I was the one caring for these animals, not someone more callous. That the experiments I did were not the worst kind. That it was for the greater good. Layer after layer of justifications driven by cognitive dissonance. 

Throughout all of this, I genuinely tried to do right by the mice in my care. I ordered enrichment tunnels and nesting material that were not used at my university. I added running wheels to their cages. I made sure no mouse was ever housed alone, and I was meticulous about pain relief after surgeries.

Mice in a lab

I did a thorough literature review on rodent analgesia and discovered that the standard painkiller doses recommended at many institutions, including my own, failed to adequately cover post-surgical pain.

I wrote a detailed letter to the animal center at my university arguing for updated protocols. After some time, they included a long-acting painkiller in their recommendations for certain procedures, yet kept the common doses unchanged. 

I also learned the truth about CO₂ euthanasia. During our training, CO₂ was presented as a humane method of killing, quick and painless. The word euthanasia itself means 'good death'. Most researchers genuinely believed that rodents did not experience any distress during the procedure. Nobody taught us otherwise.

But there is conclusive evidence that CO₂ is aversive, that animals show clear signs of distress and panic before losing consciousness, and that the gas can cause burning sensations to eyes and throat.

Millions of laboratory animals worldwide are killed this way every year. Once I understood this, I took it upon myself to kill mice that were destined for gassing by first anaesthetising them and then, once unconscious, performing cervical dislocation to spare them the panic of suffocation. 

But no matter how much care I put in, I was still working within a system that treats animal suffering as an acceptable cost of doing science. Individual effort can only do so much when the rules themselves are the problem. 

Guilt accumulated anyway. What I was experiencing has a name: moral injury, the deep conflict that comes from acting against your own values. It accumulated until I burned out completely. I became so depressed that I had to take six months of medical leave.

When I returned, I vowed never to work with animals again.

Mouse in a lab

Leaving was not simple though. I negotiated with my supervisor and we agreed that I would stop doing animal experiments and focus on analyzing my data and writing instead. For a time, colleagues pressured me to let them continue experiments on my behalf. In a vulnerable moment, I let one of them do so, and the guilt returned immediately.

The culture of animal research discourages dissent and silences ethical conflict, and many researchers endure quiet suffering to preserve career stability. 

I went vegan, and I will be for life. Even so, I am still in that same academic environment as I finish writing my thesis. I still walk past the animal facility, still sit in meetings where new experiments are discussed as routine. 

I am in a much better place now. Yet a deep sadness arises in me when I think about the mice I killed. They were individuals with the capacity to feel fear and pain, but also joy and curiosity, and they deserved better than what I gave them. 

I have spent a lot of time sitting with guilt. But I have slowly come to understand that guilt, once it has led to genuine change, has served its purpose, and so I let it go. I cannot undo what was done or bring those animals back. What I can do is refuse to participate any longer and try to prevent others from going through what I went through.

If I could go back in time with everything I know and feel now, I would choose differently in an instant. I understand that now, and I have made peace with the person I was then. 

I share this because studies suggest that 80% of researchers working with animals experience some degree of compassion fatigue, yet the conversation is often discouraged. In the meantime, the animal and human suffering continues on a vast scale, often sustained by inertia rather than genuine necessity.

If you are a researcher who recognizes yourself in any of this, I want you to know that you are not alone and that it is okay to talk about it.

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By Noah

[Name changed to protect the author’s privacy.]